Sunday, 3 May 2009

H1N1 Flu is resistant to Tamilflu

"According to the CDC, in the flu season of 2007-8 only 12% ofcirculating H1 flu viruses were resistant to Tamiflu. This season 98%of them are, for reasons not yet understood. "

At least 98% of them, but so far no resistance shown by the currentSwine Flu.

The seasonal flu is also called H1N1 but it originates from PIgs. Itkilled millions every year but only to the most vulnerable. Theycontrol it using vaccines but not by controlling the originator ofthis virus, i.e. PIGS.

Malaysia must stock Relenza as well because H1N1 flu does not haveimmunity against it yet.

From The Sunday TimesMay 3, 2009Mutant fears over 'mild flu'Experts say swine flu appears less virulent than the typical seasonalvirus, but are still concerned about its future pathmarket - swine flu

Local residents wearing face masks shop at the Central de Abastosmarket, one of the biggest in Mexico CitySteven Swinford and Tony Allen-Mills in Mexico City

The meeting was only short, but it was enough to give Barry Greatorexa dose of swine flu. Ten days ago the 43-year-old project manager fora freight company travelled to Castle Donington in Leicestershire tosee a colleague who had returned from a holiday in Mexico.

"I was just in her office and was probably only there for half an houror so having a conversation with her," Greatorex said yesterday fromhis home in Chipping Sodbury, Gloucesterhire. "In that period of timeI seemed to have contracted it. She had a cough and that's seeminglywhere I got it."

Last Monday the symptoms began. "The first two or three days werepretty horrible," he said. "Each day was worse, starting with chestpains and then the fever."

Eventually he was put on antiviral drugs and the pain eased. "I have arunny nose now and a bit of a cough, but I'm feeling a lot better," hesaid.Related Links

* Swine flu – schoolgirl among new British cases

* Ryanair boss - only 'slumdwellers' at risk

* LIVE: latest news on swine flu

Greatorex's experience was being repeated across Britain as the virusspread with alarming speed. Children at a primary school in Paignton,Devon, were in tears after it was confirmed that a 12-year-old girlhad contracted swine flu.

Yesterday morning Graham Young, an oil-rig worker, was flown toAberdeen from the North Sea after concerns that he had been exposed tothe virus. Last weekend he was drinking with his friend, GraemePacitti, 24, the first victim of human-to-human transmission of swineflu within the UK. Pacitti is thought to have contracted the virusfrom Iain Askham, the Falkirk man who, with his bride, Dawn, becamethe first confirmed UK case after honeymooning in Mexico.

By the end of the week 15 cases of swine flu had been confirmed inBritain, as far apart as Merseyside, Tyneside, London and Bristol.This weekend more than 600 samples were being tested for the virus.

As the week progressed, experts issued a procession of dire warnings.Some compared the virus with Spanish flu, which killed an estimated50m people worldwide in 1918-19. Both viruses are of the same strainand are mainly affecting people aged between 25 and 45.

Professor Neil Ferguson, an epidemiologist at Imperial College,London, warned that up to 40% of the population could become ill inthis outbreak.

Robert Madelin, the European commission's most senior health official,said: "The question now is not whether people will die, but whether itwill be thousands, tens of thousands or hundreds of thousands."

The warnings reached fever pitch on Wednesday when Margaret Chan,director-general of the World Health Organisation (WHO), raised theglobal alert from phase four to phase five, one below the maximum.This meant that a pandemic, in which a disease spreads rapidly fromcontinent to continent, was imminent. "It really is all of humanitythat is under threat," she said.

This week the Department of Health will post leaflets to everyhousehold urging people to find "flu friends" who can bring themgroceries and supplies if they fall ill. It will also dispatch bundlesof antiviral drugs to hospitals and clinics.

Yet despite the preparations and warnings, the number of deathsremains small. To date, 17 countries have confirmed more than 700cases of H1N1, although the figures are rising constantly, with just17 deaths having been directly attributed to it. All bar one were inMexico, where the virus is believed to have originated. The exceptionwas a two-year-old Mexican boy who died on a visit to Texas.

In the UK, swine flu is producing mild symptoms, almost identical tothose associated with seasonal flu. The virus is also responding wellto treatment from the antiviral drug Tamiflu.

At Newcastle University, where a new case was discovered on Thursday,Ellis Hanson, a 20-year-old fine arts student, said she and herfriends were not concerned because they remembered previous scaresabout bird flu and Sars. "We have exams coming up and people areworrying more about them," she said.

Is her sang-froid justified? Just how severe will a potential flupandemic be? Why is it killing only people in or from Mexico? And whyare scientists and the WHO so concerned?

Behind a table piled high with strange-looking herbs, tangled weedsand strips of bark, an elderly man who said his name was Christianproduced a small plastic bag stuffed with what seemed to be tea leavesand twigs.

The concoction smelled vaguely of peppermint and, according toChristian, would "build up your defences against the virus". The womanhanded over 10 pesos (about 45p).

Thousands of Mexicans took a conventional approach to the swine fluthreat, and queued for hours last week to see doctors at hospitals andclinics. Yet Salazar's preference for alternative medicines reflecteda popular Mexican tradition that officials believe almost certainlycontributed to a dangerous delay in the initial diagnosis of swineflu.

"When Mexicans fall ill, they first try to cure themselves," saidEdmundo Bermudez as he queued at a nearby chemist. "It's easy to getdrugs here without a prescription, so you just go to the chemist andsay, 'I'm not feeling well, give me some penicillin'.

"Everyone here thinks penicillin cures everything. But go to a doctor?That's expensive, and then he sends you to hospital and you have towait all day. For many of us that means missing work and losing pay."

A lingering enthusiasm for traditional herbal medicines remains potenteven in sophisticated cities. In rural areas they are often the norm.

"People wait too long to go to doctors," agreed Marcelo Noguera,undersecretary of health for the state of Oaxaca, where the firstfatality in the outbreak was recorded.

The high fatality rate among Mexican victims – compared with the muchless severe effects of the virus in other countries – was being blamedlargely on initial delays in seeking treatment and on possiblecomplications from misdiagnosis and inappropriate medicine.

Some of these factors appear to have been present in the death ofAdela Maria Gutierrez, who fell ill at the beginning of April. Shetreated herself with aspirin and waited three days to see a doctor whothen gave her antibiotics for a sore throat.

She was reluctant to leave work to go to hospital – where, it laterturned out, there were Easter-related staff shortages and no availablerespirator. By the time specialists realised she might have a rareform of flu, it was too late to save her.

One senior Mexican epidemiologist last week blamed "the idiosyncrasiesof Mexicans" for a shared suspicion of hospitals or anything run bythe government; less easy to explain was why Gutierrez died while manypeople who came into contact with her – including her husband Luis –have displayed no symptoms of the virus.

Even in the country worst hit by the flu, opinion polls last weekindicated high levels of public scepticism about the government'shandling of the crisis – notably its confused and contradictoryannouncements about the numbers of people infected.

On Friday health officials said that of 908 samples from apparentvictims tested in the latest batch sent to America for assessment,only 397 came back positive, suggesting that the overall numbers maybe below the 2,500 suspected. Yesterday the Mexican government revisedthe number of suspected swine flu deaths in the country from 176 to101.

The capital's hospitals and clinics were also strangely quiet for thesupposed centre of a global flu pandemic. On Friday at the city'sbiggest hospital, only a handful of relatives waited anxiously forfamily members who were feeling unwell. "It's very quiet," said anurse at the gate. "We are seeing no more people than usual."

Left-wing critics of President Felipe Calderon's government were quickto suggest that the authorities had deliberately inflated the threatof a pandemic to take credit for resolving a much milder crisis. Partof his prescription was an enforced five-day public holiday thatstarted on Friday.

"They have been sowing a climate of fear and psychosis," claimed atrade union leader who addressed fewer than 100 communist faithful ina brief May Day rally at the capital's main square, the Zocalo.

Ricardo Monreal, a leftist senator, said of the government's virusdata: "These are overly conservative numbers and they seem to behiding something." MODERN diagnostic techniques and the internet,however, guaranteed that the secrets of the virus could not be hidden.The first reports of a novel flu emanating from Mexico sparked aworldwide race to unpick the virus.

Last weekend the Centers for Disease Control (CDC) in Atlantapublished the DNA sequences of several virus samples in an onlinepublic library. Since then more than 30 swine flu samples have beenmade available by scientists.

These virtual viruses are being pored over by hundreds of scientistsas they search for clues about swine flu's origins, itsinfectiousness, virulence and susceptibility to antiviral drugs.Despite the WHO's gloomy prognosis, initial analysis suggests thevirus may not be as lethal as first thought.

In the US scientists have found that the virus differs significantlyfrom the strain that brought such carnage in 1918, lacking an aminoacid that increases the number of virus particles in the lungs andmakes the disease more deadly.

In many cases, previous exposure to other viruses may also be givingpeople a level of natural immunity.

Ralph Tripp, an influenza expert at the University of Georgia, hascompared the virus with the 1957 flu pandemic strain, which killed upto 2m people worldwide. His early analysis of the protein-makingstructure suggests they are similar. As a result, exposure to theearlier pandemic may be giving the elderly a higher level of immunity,as seems to be the case in Mexico where the disease has mostly killedyoung adults.

According to Wendy Barclay, chairwoman of influenza virology atImperial College, London, the swine flu looks like a mild strain. Itis an H1N1 virus, the same type as seasonal flu which circulatesaround the world every year and kills about 0.1% of those infected.

The virus tends to attach to receptors on cells in the upperrespiratory tract, the nose and the throat, causing mild illness butspreading easily through coughs and sneezes. By contrast bird flu,H5N1, attaches deep in the lungs and causes severe illness.

Professor Alan Hay, director of the WHO's World Influenza Centre inMill Hill, north London, is encouraged by the similarities. His teamis analysing a live sample of the virus and assessing whether peoplemay already have a level of natural immunity.

If so, swine flu may ultimately prove no more deadly than seasonalflu, which nevertheless kills up to 12,000 people a year in the UK andup to 1m worldwide.

Hay said: "The viruses are related. That means there is a chance thatwe have natural immunity. The difficulty is that people have beenprimed with the bird flu horror stories about pandemics, which was apretty horrendous scenario.

"This might not be any more virulent than normal seasonal fluinfections. We feel reassured that if this develops into a pandemic itmight not be a particularly severe one."

Some scientists are consequently becoming increasingly concerned bythe levels of hype and fear surrounding the virus.

Tripp warned that the WHO is failing to keep the risk in perspective,especially after Chan's comment that "all humanity is under threat".

"They should just tell the facts and not extrapolate anything," hesaid. "[The statement] is clearly her opinion – it's completelycomment, not impartial fact."

Frank Furedi, professor of sociology at the University of Kent, said:"They [the WHO and other researchers] have adopted this language wherethey continually assume the worst case scenario. It means we lose theability to make balanced assessments of risk.

"It is like the boy who cried wolf – if we react with this level ofhysteria now, what will we do when a really bad pandemic comes along?"SO are the warnings and preparations by governments out of kilter?

Even though the virus is relatively mild, it is highly contagious,meaning it has the potential to infect so many people that a largenumber could die.

Nikki Shindo, a medical officer at the WHO, said: "Even though thefatality rate is relatively low we will see a lot of people dyingbecause of the large number of people being infected. As more and morecases are reported in the US, we are starting to see somehospitalisations and more severe cases. We may see the same pattern inthe UK."

The lingering fear is that the virus will mutate into a more lethalform. Barclay said: "We need to watch out for whether this virus willchange. Often viruses that have jumped species and found new hosts areunder considerable pressure to adapt."

The WHO is also concerned that the virus will develop a resistance toTamiflu, the world's drug of choice in the fight against a pandemicflu outbreak. There are already ominous signs.

According to the CDC, in the flu season of 2007-8 only 12% ofcirculating H1 flu viruses were resistant to Tamiflu. This season 98%of them are, for reasons not yet understood.

The prospect of swine flu developing a spontaneous resistance toTamiflu, or swapping genes with an existing resistant H1N1 strain, isalarming officials at the WHO. "It is a big concern," said Shindo.

There is another treatment option, however. The UK has stockpiled 12mdoses of Relenza, an antiviral that has also proved effective attreating swine flu. H1 viruses have no resistance to it.

The government has stockpiled twice as much Tamiflu, however, and lastweek it ordered 15m more doses, making the ratio of Tamiflu to Relenzaalmost four to one.

Hugh Pennington, emeritus professor of bacteriology at AberdeenUniversity, said stocks of Relenza in Britain should be increased.

"We have to get as much as possible because we don't know howeffective Tamiflu will be," he said. "There is an issue of Tamifluresistance. All things being equal, it would be nice to get as muchRelenza as we can get our hands on. No one really knows if Tamifluwill significantly reduce transmission; the expectation is it will,but we don't know for sure."

The only long-term solution to a pandemic would be to develop avaccine.

At present four laboratories worldwide, including the NationalInstitute for Biological Standards and Control in north London, areworking with the live virus to find one.

The scientists will take the genes that make swine flu's outer coatingand attach them to a harmless human virus called PR8. Thisreconstructed virus is safe for humans, but triggers an immuneresponse that specifically protects against the swine flu strain.

The process, however, is slow. Scientists estimate that it will takethree weeks to make a seed vaccine, then a further four to six monthsto grow enough for mass distribution.

It is also not without controversy. To accommodate the mass productionof a pandemic flu vaccine drug, manufacturers will have to scale backproduction of the annual winter flu jab for the elderly and othervulnerable groups.

Ministers admitted last week that there would be a significant "publichealth difficulty" if the WHO ordered companies to switch production.

Eric Althoff, a spokesman for Novartis, the Swiss pharmaceuticalcompany that is one of the world's biggest vaccine manufacturers,said: "The WHO will be trying to balance the benefits of producing apandemic flu vaccine against the risks of halting production ofseasonal flu vaccine. It is a difficult choice." THIS weekend the WHOwas preparing to declare a full-blown pandemic. According to itsexperts the swine flu alert is likely to be raised from phase five tosix in a matter of days, despite its being a relatively mild strain.The move will leave the government continuing to tread a fine linebetween raising public awareness and avoiding scare tactics.

Sir Liam Donaldson, the chief medical officer, has to date beennotably restrained, refraining from discussing the number of peoplewho could be killed and from the alarmist language of the WHO.

Many in the forefront of treating the virus fear the line has alreadybeen crossed, with the public mistrusting what they have heard fromofficial sources.

One doctor who treated a swine flu sufferer last week said: "Thepatient was terrified when he got it. It's really been talked up. Thistime last week we were all incredibly worried because the reportscoming out were that hospitals were full and people were dying allover the place.

"We have this awareness of the 1918 epidemic which had a very, veryhigh mortality rate. But actually we are getting much more relievedthat it doesn't seem to be severe. In terms of severity the symptomsare unpleasant – fevers, shivering, aches – but not severe. Ourpatient made a full recovery.

"The way they [the WHO] are talking you would think our culture iscollapsing."

Additional reporting: Ronald Buchanan

Dealing with the dread factor

As a species, we are poor at assessing risk, writes Hugh Aldersey-Williams. Evolution has equipped us well to deal with immediate danger– our senses alert us when we prepare to cross the road or tasteunfamiliar food – but we have no way of measuring dangers further off:that is to say, risks.

We find it easy to imagine risks but impossible to assess them. As Iwrite, I have no practical idea what's the greatest risk I face. Avirus might fly in through the window, a plane might crash on theroof.

More likely, perhaps, a rat might chew through the wiring and start afire. But I can't make the assessment.

Statistics don't really help. They appear to us as cold, abstractnumbers. There's no way to relate them to the visceral horrors wecreate in our mind's eye.

Even if I could get hold of a figure for the likelihood of a rat-induced fire, I couldn't be sure it was valid for my circumstances andI still wouldn't have a basis for comparing it against all the otherhazards I face.

As a result, we underestimate the risk where the context seems benign,such as that from x-rays, and overestimate it where there is a highdread factor – in the cases of, say, nuclear power, terrorism or knifecrime.

Sigmund Freud gave three core reasons for human anxiety. The first twoare our failing bodies and nature's might, which cover our fear ofdisease and disaster. The third agent of worry is social aggravation:we can talk ourselves into a state of fear.

Our response to risk is negotiated over the dinner table and by thewater cooler. Worried about the economy, migrant workers taking yourjob, or your children's school? Well, then, talk about it. It's how wedecide what to worry about.

That is why there has been little panic about the spread of swine flu.The national conversation recalls the bird flu scare of 2005-6.Alarming government figures were published suggesting that a quarterof Britain's population would be infected and that 1 in 100 might die.The outbreak never came.

A rational response then was to observe that while probably nobodywould die of bird flu in Britain, the usual 12,000 people a year werepretty sure to die of ordinary flu, a disease too chronically boringto write headlines about. This time the virus is a type of ordinaryflu. That is why planning, and not panicking, seems to be the order ofthe day.

Hugh Aldersey-Williams is the co-author with Simon Briscoe ofPanicology (Penguin)

Is this the bird flu scare revisited?

Why all the fuss? Influenza is a virus that constantly changes, someversions being mild, others lethal. The current outbreak of swine fluis causing concern because many of the 101 people believed to havebeen killed by it in Mexico have been young and middle-aged, ratherthan the elderly and infirm, the usual victims of flu.

But hasn't only one person outside Mexico died? Yes, and that victimwas a child in the US who had come from Mexico. The disease may indeedbe a mild form of flu, but it's too early to tell for sure. What isclear is that it has spread worldwide and that it can transfer notjust from pigs to humans, but from human to human.

Why is this called a "pandemic" when ordinary flu is not? Flu virusescirculate all the time, usually causing epidemics in winter intemperate countries. A pandemic occurs, according to the World HealthOrganisation (WHO), when a new flu virus appears against which humanshave no immunity, resulting in outbreaks worldwide. The swine fluvirus, even though it has yet to kill large numbers – and may never do– meets this criterion.

Why does everyone mention 1918? The "Spanish flu" of 1918-19 was theworst pandemic in modern history. A new flu strain emerged that,unusually, was most deadly for those aged between 20 and 40. Many arethought to have suffered "cytokine storms" – massive overreactions ofthe immune systems. An estimated 50m people worldwide died. Remember,however, that mortality rates may have been high because livingconditions and medical treatments in 1918 were nowhere near asadvanced as they are in many countries today.

If we're not at that point, why is the WHO saying "all humanity" is atrisk? There hasn't been a significant pandemic for decades; youngergenerations may have low immunity; modern travel spreads diseasefaster than ever. All these factors mean a virulent new virus couldcircle the globe very rapidly.

How does the virus spread? Mainly through tiny airborne droplets fromthe coughs and sneezes of infected people. Carriers can becomeinfectious a day before they show symptoms of flu. The virus can alsosurvive for several hours on an inanimate surface, such as a doorhandle. If you pick up the virus on your hands and then touch yourmouth, nose or eyes, it can still infect you.

So what can I do to protect myself? Avoid people who have the flu andare coughing and sneezing, and wash your hands frequently.

What about a face mask? They are better than nothing if you cannotavoid infected people – but they are not designed to stop fluinfection and you may still inhale the virus even if you are wearingone.

What should I do if I get symptoms? Consult the NHS website, which hasa "symptom checker", for advice or ring the government's advice lineon 0800 1 513 513. If your symptoms are confirmed, ring your GP or NHSDirect. Do not go to your doctor in person.

Can medicine save me? Swine flu H1N1 is at present treatable with adrug called Tamiflu, which the government has stockpiled. However, asflu viruses mutate they can develop resistance to drugs. Scientistsmay also develop a vaccine against swine flu, though this will takemonths. Remember: even in the 1918 pandemic only a tiny fraction ofthose infected died. Most people recover naturally.

Is this a rerun of the bird flu and Sars panics that came to nothing?Possibly, though it's too early to say. But with flu pandemics,officials err on the side of caution.